Alright, after some stuff these past few weeks and with trying to get everything lined up for some classes, it was brought to my attention that I needed to have a more "conventional" setup in my arsenal for training.
I'm planning on getting down to Gunsite in the next year, and I also want to take a Magpul carbine course some time in the next year as well. For LE courses, I need to have a more conventional setup, and the PDW/PSD build I just finished doesn't fit the bill.

This rifle will primarily be a training rifle for instructor recertifications, as well as training where a more conventional AR/M4 carbine is required. The M4CQB will fill the gap between the standard 14.5" M4 and the new 10.3" Mk18. The decision was made to make this the most rugged DI carbine possible, so a fixed front sight post was integrated into the build, along with mil-spec designed parts.